In connection with a vehicle which is provided with a compressed-air system for producing, storing and distributing compressed air to, for example, the air suspension system and the brake system, which in a manner known per se includes pressure tanks, compressed-air lines and various types of valve, said system is supplied with compressed air from a compressed-air compressor. Said compressor is driven in a manner known per se by means of the internal combustion engine of the vehicle. To lubricate the compressor, use is made, according to the known art, of lubricating oil from the lubricating oil system of the internal combustion engine.
In accordance with previously known art, the compressed air can be fed from the compressor to the compressed-air system of the vehicle. A problem which occurs in previously known compressed-air systems of the abovementioned type is that the compressed air which is generated in the compressor is often contaminated by lubricating oil in aerosol and gaseous form. During operation of the compressor, a very high temperature is reached, which can lead to oxidation of the lubricating oil mixed into the compressed air, which can result in polymerization of the oil and the formation of aggressive oxidation products. If these contaminants were to be conveyed to the rest of the compressed-air system of the vehicle, coatings could be formed in the components of said system. These coatings can cause clogging and corrosion of the material of said components, which can in turn cause failure of the components.
According to the known art, the compressed air generated in the compressed-air compressor can be cleaned by means of a mechanical filter combined with cooling. A disadvantage of this technique, however, is its low degree of efficiency.